The influences of Tylosine and licorice dietary supplementation in terms of the productive performance, serum parameters, egg yolk lipid profile, antioxidant and immunity status of laying Japanese quail under heat stress condition

By reducing feed consumption, animals suffering from heat stress prefer to reduce their heat output. Heat exposure has also contributed to major adverse effects on the productive and reproductive performance of quails. Therefore, this research was intended to estimate the preventive function of licorice as a safe feed additive against the negative effects caused by heat stress conditions on laying quail productivity. A total number of 180 Japanese quail birds (120 females and 60 males), nine-weeks old were divided into five groups. Each group contained 36 birds in four replicates (nine birds) with completely randomized design. The dietary treatments were a basal diet without supplementation as control (T-1), basal diet + 100 mg Tylosine kg(-1) diet (T-2), (T-3), (T-4) and (T-5) fed basal diet + 250, 500 and 1000 mg licorice kg(-1) diet, in respect. The results indicated that dietary supplementation with different feed additives had no significant effects on egg-laying rate, egg number, average egg weight, egg mass and feed conversion ratio compared with control. Also, different treatments showed no significant variations on serum IgG, total protein, globulin, albumin, creatinine, ALT and TAC and caused significant (P <= 0.05) improvement in IgM, AST, ALP, uric acid and MDA concentrations as compared to the control. Results indicated that total serum lipids, triglycerides, total cholesterol and LDL concentrations were significantly decreased due to different feed additives. However, HDL concentrations and HDL/LDL ratios were markedly increased by the other treatments than the control group. In addition, yolk total lipids were significantly (P <= 0.001) decreased with increasing licorice root powder's dietary levels compared with the control group. Also, a significant (P <= 0.01) reduction in egg yolk cholesterol level was observed in the group fed with 500 mg licorice compared to other treatments. In conclusion, fortified laying quail diets with licorice powder could be a useful strategy to alleviate adverse effects induced by heat stress as alternative to antibiotics on laying Japanese quail.

Automated summary

The study found that dietary supplementation with different feed additives did not significantly affect egg production performance. However, improvements were observed in certain blood parameters with different feed additives compared to the control group. Results also showed significant decreases in serum lipids and cholesterol concentrations due to various treatments, while HDL concentrations increased. In conclusion, fortified quail diets with licorice powder could be a beneficial strategy to mitigate heat stress effects on laying Japanese quail.